Low Detection Limit Research Articles

An ESIPT based fluorochromogenic tweezerfor reversible and portable detection of Al3+ ions.

ESIPT-based fluorochromes are promising materials for the detection of various chemical/biological species, especially the metal cations. Herein, we elaborately designed a prototypical ESIPT-active ɑ-naphtholphthalein- derived "turn-on" fluorogenic tweezerNPDM for selectively detecting and visualizing Al3+ in biological and environmental samples. NPDM was found to specifically interact with Al3+ with dual emissions, good sensitivity (50 s), large Stokes shifts (140 nm/176 nm) and low detection limit (16.3 nM). Noteworthily, the sensing mechanism of NPDM towards Al3+ has been supported by Job's plot, HRMS, 1H NMR titrations, as well as detailed DFT calculations. Interestingly, the NPDM-Al3+ ensemble can act as a secondary chromo-fluorogenic tweezers for monitoring F- with a low detection limit down to 34.8 nM level. Thus, an advanced molecular memory device was constructed based on the fluorescence ''off-on-off" strategy and its excellent sensing properties. Moreover, a portable smartphone-aided intelligent platform was fabricated to realize the portable detection of Al3+ in real samples. Significantly, NPDM was successfully employed for imaging the intracellular Al3+ and F- ions in Hela cells without interference from the oxidative stress and it is the first reported smart molecular tweezers capable of determining the Al3+ ions formed during electroporation inside living cells.

Decreasing matrix effects for accurate analysis of primary aliphatic amines in skin moisturizers using magnetic adsorbent

In this study, for analysis of primary aliphatic amines present in skin moisturizer samples, a dispersive micro solid phase extraction method using a mercaptoacetic acid-modified magnetic adsorbent (MAA@Fe3O4) was developed to eliminate matrix effects (while not adsorbing the studied analytes). This approach was combined with vortex-assisted liquid-liquid microextraction for the simultaneous derivatization and extraction of primary aliphatic amines present in these samples. To confirm the successful synthesis of the adsorbent, various characterization techniques were employed, including X-ray diffraction, Brunauer-Emmett-Teller surface area analysis, scanning electron microscopy, Fourier transform infrared spectrometry, energy-dispersive X-ray, thermogravimetric analysis, and vibrating sample magnetometry. ComplexGAPI software and analytical eco-scale index were employed to evaluate the greenness of the method. All key parameters affecting matrix cleanup, derivatization, and extraction were optimized. A gas chromatograph equipped with a flame ionization detector was used for the identification and quantification of the amine derivatives. The method demonstrated high unadsorbed percentage of the analytes (92–97%), significant enrichment factors (420–525), wide linear ranges (1.6–10,000 µg L− 1), excellent precision (1.4–2.7%), and low limits of detection (0.5–0.82 µg L− 1). This approach offered several advantages, including eco-friendliness, short extraction time, high matrix removal efficiency, simplicity, excellent precision, no need for specialized equipment, and adsorbent reusability for up to five cycles. The method also proved highly effective in the simultaneous extraction and derivatization of amines, further highlighting its potential for analytical applications.

Fluorescent bead-based multiplex assays improve serological disease diagnostics and have potential of identifying sensitive immune biomarkers for maintaining health and performance.

Fluorescent bead-based multiplex assays (multiplex assays) for serological detection of antibodies in patient samples have been used in veterinary diagnostics for a little over a decade. These quantitative assays offer several advantages compared to classical serological assays, like a lower limit of detection, less background, and a broader linear quantification range, all of which improve test accuracy. The simultaneous multiplex analysis of a patient's serological response to several specific antigens also improves the diagnostic result interpretation. This influences treatment and management decisions and often allows for a quantitative follow-up as treatment response evaluation. In this review article, we discuss examples of 3 diagnostic multiplex assays for antibody detection in veterinary patients: the Lyme Multiplex assay, the Canine Brucella Multiplex assay, and the Equine Herpesvirus Type-1 Risk Evaluation assay. In addition, multiplex assays for immune response markers, like soluble cytokines, chemokines, or other inflammatory proteins, have recently become available. Currently, these assays are mainly used as clinical research tools to broadly evaluate immune activation and/or inflammation during a variety of infectious and noninfectious diseases. Quantitative cytokine and inflammatory marker multiplex assays have the potential to identify sensitive immune biomarkers for maintaining health and performance in veterinary animals.

A deep dive into four thyroglobulin immunoassays from analytical perspective

Backgrounds Serum thyroglobulin immunometric assays (sTg) are crucial for monitoring differentiated thyroid cancer (DTC) treatment. However, challenges such as anti-thyroglobulin autoantibodies (TgAb) and assay variability hinder evaluations. This study assessed four sTg methods—three second-generation (Architect, Access, Elecsys) and one first-generation (Immulite)—following Clinical and Laboratory Standards Institute (CLSI) and American Thyroid Association (ATA) guidelines. Methods The study compared sTg(Architect), sTg(Access), sTg(Elecsys), and sTg(Immulite). Precision was evaluated per CLSI EP05-A3, while the lower limits of detection (LLD) were assessed using EP17-A2. Passing–Bablok and Bland–Altman analyses were conducted as per EP09c, and semi-quantitative comparisons used Kappa statistics. Results The second-generation sTgs (Architect, Access, Elecsys) exhibited satisfactory precision (<7% coefficient of variation, CV%), unlike sTg(Immulite), which showed significant deviations and inadequate sensitivity for DTC recurrence (Limit of quantitation, LoQ = 4.59 μg/L). Second-generation sTgs had strong correlations (r > 0.884) across all concentration ranges (≤1, 1-10, >10 μg/L), with biases (slope: 1.131-2.027). sTg(Immulite) correlated well with second-generation methods for concentrations >10 μg/L (r > 0.945) but less so for <10 μg/L (r < 0.642). TgAb significantly impacted sTg(Immulite). Kappa statistics revealed strong agreement among second-generation methods (κ > 0.800) but lower concordance with sTg(Immulite), especially in TgAb(+) samples (κ: 0.562-0.653). Agreement ratios were high for second-generation methods (0.667-1.000) but variable for sTg(Immulite), particularly at lower concentrations and in TgAb(+) cases (0.097-0.727). Conclusions sTg(Immulite) did not meet LLD and precision criteria for DTC monitoring, facing issues with TgAb interference. Second-generation sTgs demonstrated consistent performance across all concentrations.

Synergistic Structural Construction of Strain Sensors with Low Baseline Drift and High Sensitivity for Continuous Dynamic Monitoring.

Strain sensors based on conductive elastomers face challenges like baseline drift and noise due to inherent viscoelasticity and weak electrode interfaces under dynamic strains. Herein, a synergistic structure with biphasic hierarchical networks and stable electrode interfaces is proposed to address these issues. The sensor employs a multilayer structure with polydimethylsiloxane (PDMS) substrate, carbon nanotube-doped PDMS (CNT-PDMS), and Ag film. Electrodes are fixed using a rigid island reinforced mortise and tenon joint formed with PDMS and CNT-PDMS. The Ag film dominates resistance during release, significantly reducing baseline drift. Strain-insensitive electrode interfaces further reduce baseline drift and noise. This optimized design ensures 99.999% resistance recovery without delay, even at high-speed (800 mm/min) and large (80%) strains. The sensor exhibits a high gauge factor of 55442, low detection limit (0.02%), and excellent stability (5000 cycles). With the designed algorithms, the single-channel sensor achieves 98.2% decoding accuracy for various gestures, demonstrating great potential for wearable electronics.

Superior sensitive graphene fiber sensor enabled by constructing multiple nanoembossments for glucose detection

Metal oxides have been extensively investigated in non-enzymatic biosensors for detecting diabetes owing to their electrochemical catalytic properties and excellent stability. However, lower conductivity and catalytic activity are major obstacles to the commercialization of metal oxide-based non-enzymatic glucose sensors. Herein, we present a novel flexible nonenzymatic glucose sensor utilizing graphene fiber (GF)/Au/Ni(OH)2 composite fiber. The integration of GFs enables a significant uptake of sensing molecules due to its expansive surface area and high electron mobility, ultimately resulting in a decrease in the detection limit. Consequently, the incorporation of Ni(OH)2 provides abundant attachment sites by introducing Au atoms, thereby promoting electron migration and enhancing sensitivity and detection limits. An impressive sensitivity (1095.63 µA mM−1 cm−2) within the detection range (5 µM–2.2 mM) of the integrated GF/Au/Ni(OH)2 fiber is achieved, leading to an incredibly low detection limit (0.294 µM). Additionally, the outstanding repeatability, anti-interference properties, and flexibility of the GF/Au/Ni(OH)2 sensors are obtained as well. Our findings offer a novel method for constructing nano embossments on GFs to achieve superior glucose detection capabilities in the field of wearable electronics in the future.

2‐Bromonaphthalene‐Induced Defect Passivation to Suppress Ion Migration in CsPbBr3 Wafer for X‐Ray Detector with Bias‐Resistant Stability

AbstractFeaturing exceptional photoelectronic properties and scalability, hot‐pressing processed all‐inorganic (i. e., CsPbBr3) perovskite wafers have emerged as promising candidates for direct X‐ray imaging. Nonetheless, severe ion migration in CsPbBr3 wafers results in a large and drifting dark current, thereby compromising the bias‐resistant stability of the X‐ray detector. Herein, a solvent‐free interfacial defect passivation strategy is proposed by introducing a passivator molecule, 2‐bromonaphthalene, to passivate interfacial defects and suppress ion migration in CsPbBr3 wafers. Implementing this strategy effectively inhibits ion migration in CsPbBr3 wafers, as evidenced by an enhanced ion migration activation energy of 0.56 eV and a negligible dark‐current drift of 4.01 × 10−8 µA cm−1 s−1 V−1, representing a 100 fold reduction in dark current drift compared to untreated CsPbBr3 wafers under a high electric field of 100 V mm−1, indicating a high bias‐resistant stability. Consequently, the CsPbBr3 wafer X‐ray detector achieves an impressively high sensitivity of 11090 µC Gyair−1 cm−2, a low detection limit of 9.41 nGyair s−1 under a 100 V mm−1 electric field, and high‐contrast X‐ray imaging capabilities, with performance comparable to that of CsPbBr3 single‐crystal‐based X‐ray detector, highlighting the potential of interfacial defect passivation strategy for high‐performance X‐ray detectors.

Unlocking Enhanced Detection of Perfluoroalkanesulfonic Acids via Fluorinated Nonpolar 3D Covalent Organic Frameworks-Based Ambient Probe Nanoelectrospray Ionization Mass Spectrometry.

The trace levels and severe matrix interferences greatly limited the determination of stable, persistent, and long-range-transported perfluoroalkanesulfonic acids (PFSAs) in complex environments. Here, we design and prepare the first fluorinated nonpolar 3D COF (TFPM-Pa-CF3) as an adsorbent, consisting of tetrakis(4-formylphenyl)methane (TFPM) and 2,5-diaminobenzo-trifluoride (Pa-CF3) for adsorption and extraction of PFSAs. The proposed TFPM-Pa-CF3 demonstrates excellent adsorption capacity (509.1 mg g-1) and rapid adsorption kinetics (5 min) for PFSAs attributed to the synergistic effects of F-F, hydrophobic, and electrostatic interactions. Furthermore, TFPM-Pa-CF3 is grown in situ on a stainless needle and coupled with ambient probe nanoelectrospray ionization mass spectrometry (PESI-MS) to develop a rapid and direct determination method with a low limit of detection (0.05-0.86 ng L-1) and wide linear range (1-10,000 ng L-1) for trace perfluorooctanesulfonate and its alternatives in environmental soil, algae and water. This work unlocks the efficient determination or removal of PFSAs in a complex environment, facilitating the solution of critical environmental PFSAs problems.

A new β-amylase detection strategy based on encapsulated enzyme in magnetic layered double hydroxide with high sensitivity and simplified workflow.

A new β-amylase detection strategy based on encapsulated enzyme in magnetic layered double hydroxide with high sensitivity and simplified workflow.

Coulomb Field-Driven Desorption/Ionization by Femtosecond Laser for Mass Spectrometry Detection and Imaging.

Surface-assisted laser desorption/ionization (SALDI) offers promising prospects for mass spectrometry detection and imaging of small biomolecules, as it addresses most of the matrix-related issues encountered in conventional matrix-assisted laser desorption/ionization (MALDI). Currently, nearly all of the fundamental aspects and applications of SALDI depend on nanosecond (ns) lasers, whereas few efforts have been made to integrate ultrafast femtosecond (fs) lasers with SALDI. Therefore, the intrinsic fundamental principle remains poorly understood. Herein, a novel surface-assisted femtosecond laser desorption/ionization mass spectrometry (fs-SALDI-MS) platform was developed, which significantly reduces analyte fragmentation and preserves molecular integrity. Spectral interferences from surface-assisted materials and alkali-metal adducts are absent in fs-SALDI mass spectra. Ion survival yields continuously increase with decreasing laser pulse widths from 5 ns to 600 fs, highlighting a gradual transition from thermal to nonthermal effects. A lower absolute limit of detection down to ∼3 amol for representative antifungal and psychotropic drugs and clearer visualization of ultratrace drug residues on latent fingerprints can be achieved, indicating that fs-SALDI results in gentler and more efficient detection/ionization processes than mainstream ns-SALDI. The biological applicability of this method was further validated through 10 μm-spatial-resolution lipid imaging of mouse brain sections. In short, a novel Coulomb field-driven desorption/ionization mechanism is proposed for fs-SALDI, opening new avenues for the development of emerging fs-SALDI techniques with superior analytical performance.

Direct Evolution of Matrix-Resistant Circular Bivalent DNA Aptamers for Ara h1.

Peanut allergenic protein Ara h1 is a serious food allergen due to its potentially life-threatening effects, and its accurate detection holds significant importance. While several selections were previously reported to isolate DNA aptamers for Ara h1, little success was achieved for binding in a complex food matrix. In this work, circular bivalent aptamers for Ara h1 were obtained by employing a dumbell-shaped DNA library with dual random domains for selection. The highest affinity aptamer, named as CB-APT1, exhibited a dissociation constant (Kd) of 36.3 nM, as determined by microscale thermophoresis. Notably, a similar binding affinity was observed even in a complex matrix that contained 80% w/w total peanut proteins. Further analysis indicates that each random domain acts as a unique binding moiety, working together to enhance the overall affinity. Subsequently, a label-free fluorescent aptasensor was developed for Ara h1, which demonstrated a low detection limit of 1.3 nM and performed well, even in food samples. Our evolution-based approach for developing circular bivalent DNA aptamers does not rely on structural information on the target protein, making it applicable to a wide range of protein targets. We believe this strategy can be leveraged to generate a diverse set of high-quality circular bivalent DNA aptamers that are both stable and functional in real biological samples, thus enhancing the practical applications of DNA aptamers in real-world applications.

Personalized assessment and monitoring of bone health from sweat: unveiling TEGO doped wearable, non-invasive hydrogel nanocomposite biosensor empowered by IL-6 detection.

Portable biosensing is crucial for rapid detection and continuous monitoring of bone diseases such as osteoporosis and bone cancer. It is well established that such bone disorders or diseases trigger release of inflammatory cytokines including interleukin-6 (IL6), detectable in sweat by electrochemical immunosensors. To this end, this study presents a novel hydrogel nanocomposite based immunosensor with highly conductive dual-layer of exfoliated graphene oxide (TEGO), toward precise detection and determination of loading level of IL-6 biomarker, and in turn, developing a label-free flexible bone biosensing platform. The immunosensor employed antibody immobilization process, which was further facilitated by the modification of the dual-layer by using 1-pyrenebutyric acid N-hydroxy succinimide ester (Pyr-NHS). A thorough analysis of the effects of surface modification was conducted utilizing spectroscopic, electrochemical, and morphological methods. The biosensor's response was assessed through the utilization of the cyclic voltammetry (CV) measurement, which exhibited remarkable selectivity, achieving a low limit of detection (LOD) of 15.4 pg/ml across a wide linear range. Additionally, FE-SEM, FT-IR and Raman spectroscopy were successfully used to validate the sensing substrate in bio-fluidic samples and to understand the structure-property correlation. This innovative portable and flexible biosensor thus offers a practical and effective tool for potential application in continuous monitoring of bone health.

Real-Time Detection of Methylmercury and Hg(II) Using a Reversible Ratiometric Fluorescent Probe in Cellular and Aqueous Environments.

Methylmercury (CH3Hg(I)), produced by the action of aquatic bacteria on inorganic mercury, is the most hazardous among the mercury species. To date, no ratiometric fluorescent probes have been reported for the detection of both CH3Hg(I) and Hg(II) in aquatic environments and in live cells. Herein, we designed a novel fluorescent probe incorporating a peptide containing a histidine residue with self-assembly properties specific to both mercury species and a fluorophore that exhibits red-shifted emissions upon aggregation. The probe effectively detected Hg(II) and CH3Hg(I) in aqueous solutions (1% DMSO) through ratiometric fluorescence sensing with visible-light excitation (445 nm). The probe exhibited high selectivity for Hg(II) and CH3Hg(I) among 19 metal ions, rapid response times (<4 s for CH3Hg(I)), low detection limits (12.5 nM for Hg(II) and 248.6 nM for CH3Hg(I)), reversible sensing, and a broad operational pH range. As a result, the probe was successfully employed for rapid and real-time sensing of CH3Hg(I) and Hg(II) in both aquatic environments and live cells through distinct ratiometric fluorescent changes. A comprehensive binding mode study using dynamic light scattering, IR and CD spectroscopy, and NMR spectroscopy revealed that the chelation of mercury species by the peptide with the metal-binding site and the fluorophore triggers the self-assembly of the complex, enabling fast and sensitive ratiometric detection of mercury species. The combination of a self-assembling peptide with a metal-binding site and a responsive fluorophore provides a valuable fluorescent sensing platform for the detection and quantification of specific analytes, particularly in complex matrices.

An Ultra-High-Resolution Mass Spectrometer with an Intermediate-Pressure Matrix-Assisted Laser Desorption/Ionization Source.

The demand for high-resolution, high-throughput and spatially resolved mass analysis has been a key focus in developing mass spectrometers. We have developed a novel high-performance mass spectrometer by integrating matrix-assisted laser desorption/ionization (MALDI) source with a new planar electrostatic ion trap mass analyzer for ultrahigh-resolution MALDI source mass analysis. Performance characterization experiments show that with a transient time of 800 ms, the resolution for 392 Th can exceed 530 K by utilizing high-order harmonics, and the spectrometer can distinguish the isotopic peaks in the Met-Arg-Phe-Ala acetate salt (MRFA) M+2 peak family. Preliminary results also show an overall mass range from 133 to 9500 Th by stitching together multiple single scans with at least 6-fold mass range, and a low detection limit of 32 fg. Initial tests on analysis of edible oils demonstrate its capability to distinguish plant and animal oils based on triacylglycerols.

Water-stable Eu(III) coordination polymer-based ratiometric fluorescence sensor integrated with smartphone for onsite monitoring of doxycycline hydrochloride in milk.

The widespread misuse of doxycycline hydrochloride (Dox) in livestock farming has necessitated the development of rapid and reliable methods for monitoring its residues in food products. Herein, a water-stable europium coordination polymer-Eu(C2O4)1.5(H2O)ₙ (Eu-CP) with a layered structure was synthesized via a one-step hydrothermal approach. Leveraging its dual-emission properties (455nm ligand-centered blue emission and 615nm Eu(III)-based red emission), we engineered a ratiometric fluorescence sensor (I₆₁₅/I₄₅₅) for Dox detection. The sensing mechanism involves synergistic effects of the antenna effect and Dox@Eu-CP complexation, enabling selective Dox recognition with a wide linear range (10-100μM) and a low detection limit (0.46μM, S/N = 3). To facilitate onsite analysis, a smartphone-integrated platform was developed, translating the Dox concentration-dependent color transition (blue → red) into quantifiable R/G values via a custom Android application. Practical applicability was demonstrated in milk samples, achieving recoveries of 82.4-119.4% (fluorescence) and 87.8-113.3% (smartphone) with RSD < 5%. This work pioneers the integration of lanthanide coordination polymers with portable digital detection, offering a green and visual strategy for antibiotic residue monitoring in food safety.

Spinel CuCo2O4 Microflowers with Highly Exposed High-Index (112) Facets for Electrocatalytic Glucose Oxidation.

The design of nanomaterials enclosed by high-index facets plays a critical role in the surface-sensitive properties. Herein, hierarchical CuCo2O4 microflowers (CCO-F) with highly exposed high-index (112) facets are rationally designed via a solvothermal method followed by calcination. CCO-F are composed of 30 nm-thick nanoflakes and have an ultrahigh specific surface area of ca. 205.48 m2 g-1. Additionally, nanoparticle-assembled CuCo2O4 microspheres (CCO-S) are prepared, and these nanoparticles are partly enclosed by the (110) facets. Abundant octahedrally coordinated Co3+ (Co3+Oh) and tetrahedrally coordinated Cu2+ (Cu2+Td) exist in the (112) facet, especially Co3+Oh (with a density of 0.063 Å-2); moreover, the (112) facet possesses a high surface Gibbs free energy (2.7367 J m-2). Therefore, CCO-F have significant advantages of adsorbing glucose and conducting the subsequent redox reactions. In addition, the hierarchical microstructure promotes the reaction kinetics of CCO-F. Benefiting from these features, the CCO-F-modified electrode exhibits high sensitivities (1351.2 and 598.7 μA mM-1 cm-2), wide linear ranges (1 μM-3 mM and 4-10 mM), rapid response time, low detection limit, excellent stability, and good selectivity. This work indicates that the exposure of a high percentage of high-index facets is an effective approach to exploring high-performance electrocatalysts for glucose detection.

Novel Solid Contact Ion Selective Sensor for Potentiometric Analysis of Barium Ions

Barium as an alkaline earth metal is widely used in multiple industries. Due to its widespread use, it is toxic to living things in high concentrations. In this study, polymer membrane barium–selective potentiometric sensors were prepared in which 4-aminobenzoic acid 2-diethylaminoethyl ester was used as an ionophore. The prepared sensors exhibited selective and stable behavior towards barium ions. The novel barium–selective potentiometric sensor had a low detection limit of 4.23×10-6 M over a wide linear concentration range from 1.0×10-5 to 1.0×10-1 M. The sensor proposed in the present study had good repeatability, short response time (8s) and could work over a wide range of pH. The sensors prepared simply and economically were able to determine barium ions in various samples with very high recoveries.

Establishment and validation of a simple and accurate qPCR detection method for Haemophilus parasuis

As an infectious disease that poses a significant threat to the rapidly growing pig breeding industry, the detection of Haemophilus parasuis (HPS) is often compromised by various interfering substances present in the test sample during quantitative real-time PCR (qPCR). The rapid detection of HPS is important for the isolation of infectious pigs and their treatment. We designed and optimized a rapid qPCR test to detect the INFB gene of HPS in clinical and environmental samples on pig farms. The method was evaluated for its specificity, sensitivity, repeatability, anti-interference capability, and its ability to detect HPS in clinical samples. The results indicated that the method was specific for the detection of HPS when evaluated against pathogens and intestinal probiotics found in pig farms. By using a seven-fold dilution series of the recombinant plasmid DNA in triplicate, it was determined that the lowest limit of detection (LOD) for this method was less than 10 copies/µL. The results of inter-batch and intra-batch repeatability tests showed that the coefficient of variation (CV) was consistently below 1%. Furthermore, the impact of 14 endogenous and exogenous interfering substances on the Ct values detected by the HPS qPCR was found to be less than 5% when compared to the Ct values obtained in the absence of interfering substances. A total of 248 clinical samples were analyzed using the HPS qPCR, commercial kits, and corresponding national standards, yielding positive rates of 9.27%, 6.05%, and 9.27%, respectively. Notably, the positive and negative percent agreement between the detection method developed in this research and the national standard was 100%. These findings demonstrate that the established detection method is suitable for epidemiological research on HPS and for diagnosing clinical samples containing interfering substances, thereby providing essential technical support for the prevention and control of HPS.

Structurally modified carbon nanotubes as twisted fibers towards electrochemical detection of environmentally hazardous cartap.

Pesticides such as cartap play a crucial role in agriculture, as they are extensively used in controlling pests in crops like sugarcane, rice and vegetables. However, their excessive usage poses major threats to human health, causing neurotoxicity and respiratory disorders. In addition, they harm aquatic ecosystems by disrupting biodiversity. Consequently, effective detection and remediation are essential to minimize their adverse effects on human health and the ecosystem. For this purpose, an electrochemical method was used for the simultaneous detection and degradation of the under-reported insecticide cartap. In this work, vertically aligned carbon nanotube arrays were grown and converted into fibers via simple mechanical spinning and used as a flexible electrode material for cartap electro-oxidation. The fabricated electrode exhibited excellent performance towards sensing and remediation without any surface modification. The fiber-based electrode showed a wide linear range, a low detection limit (LOD) of 0.575 mM, high sensitivity (7.98 μA cm-2 mM-1), reproducibility, and excellent electrocatalytic activity. The multi-functionality of this electrode was attributed to its unique properties like flexibility, compatibility with various media (aqueous and organic), cost-effectiveness, and seamless integration with membranes, making these fibers promising candidates for on-site facile detection and long-term degradation of cartap.

Electroanalytical Immunotechnology for Minimally Invasive Assessment of Toll‐like receptor 2, a Key Inflammatory Component in Colorectal Cancer Progression

Toll‐like receptor 2 (TLR2) is involved in infectious diseases, inflammatory processes and carcinogenesis. Soluble TLR2 (sTLR2) can be released into circulation stream acting as an endogenous negative regulator of TLR2 signaling, essential for the prevention of chronic inflammation and tissue destruction. In this context, we propose pioneering electrochemical biotechnology for the determination of sTLR2 in plasma of colorectal cancer (CRC) patients. The method involves the use of magnetic particles as micro‐supports for the implementation of a sandwich immunoassay using a pair of specific antibodies and horseradish peroxidase as enzymatic tracer to carry out the amperometric transduction on screen‐printed carbon electrodes in the presence of H2O2 and hydroquinone. The proposed immunoplatform shows attractive operational and analytical characteristics, reaching a low limit of detection of 241 pg mL−1 for TLR2 standards in buffered solutions, and showing an excellent reproducibility (RSD 1.4 %), and a wide dynamic range (804 to 25000 pg mL−1). It has been applied to the analysis of a cohort of 21 plasma samples from healthy individuals and CRC patients at different stages of the disease, demonstrating precise quantitative determinations, in just 45 min and requiring minimal sample amount and pre‐treatments. The results demonstrate the promising utility of TRL2 plasma levels for minimally invasive monitoring of CRC progression.